1. Field of the Invention
The present invention relates, in general, to a method for the preparation of ketones and, more particularly, to a method for preparing novel ketones by use of a transition metal catalyst with the aid of a 2-aminopyridine derivative.
2. Description of the Related Art
Until recently, the introduction of carbonyl, one of the most important organic groups, into organic compounds has been in extensive study for preparing ketones. In one of the most typical methods, aldehyde is reacted to a nucleophilic organic metal compound, such as alkylmagnesium halide, to give bivalent alcohol which is then oxidized into ketone with the aid of various oxidizers. However, this method suffers from several disadvantages; it must pass through many reaction steps and it produces many unnecessary by-products during the reaction steps.
In an effort to avoid these problems, active research has been directed to hydroacylation techniques for preparing ketones directly from olefins and aldehyde. Of them, the preparation from aldehyde and olefins in the presence of a metal catalyst and 2-aminopyridine derivatives is actively studded for its simple feasibility under a mild conditions. According to this method, aldehyde is reacted with 2-aminopyridine to give aldimine which is then reacted with olefin through a metal catalyst, followed by hydrolysis to afford ketone. However, this method is disadvantageous in terms of high production cost and low production yield.
Meanwhile, no methods have been reported for the conversion of one ketone into a different one. In order to synthesize a new ketone from a preexisting one, the alkyl radical attached to the carbonyl group must be removed and substituted by a desired alkyl radical. There have not yet been developed methods for effectively cleaving the single bond between the carbon atom of a carbonyl group and the .alpha.-carbon atom.